WCH CH9434A

CH9434A is an SPI-to-quad-UART bridge chip that provides four full-duplex 9-wire asynchronous serial ports for expanding asynchronous serial interfaces in MCU/embedded systems. The chip integrates four 16C550-compatible asynchronous UARTs supporting up to 4Mbps baud rate communication, up to 25 GPIO lines, and a half-duplex transceiver auto-switching pin TNOW. CH9434D is an SPI/I2C-to-quad-UART and single-channel CAN bridge chip that likewise provides four full-duplex 9-wire asynchronous serial ports for serial port expansion. Its four integrated asynchronous UARTs support up to 6Mbps baud rate communication, up to 4 GPIO lines, a half-duplex transceiver auto-switching pin TNOW, and an integrated CAN transceiver controller.

• Operating voltage: 3.3V
• Configurable baud rate; CH9434A supports up to 4Mbps, CH9434D supports up to 6Mbps
• Independent FIFO buffers per UART channel: 1536-byte TX buffer and 2048-byte RX buffer
• Four fully independent asynchronous UARTs
• Configurable data bits and parity bits per UART
• Half-duplex RS485 TX/RX enable pin
• CH9434D features one CAN transceiver controller with built-in TX/RX buffers and filters
• SPI interface up to 20Mbit/s
• Low-power sleep mode with host interface wake-up support
• Configurable GPIO
• CH9434A requires external 32MHz crystal for clock; CH9434D supports internal clock or external 16MHz crystal
• CH9434A in QFN48 package; CH9434D in QFN20 package; both lead-free and RoHS compliant

• Microcontrollers / DSPs / Embedded Systems
• Industrial Automation
• Serial Servers & Multi-port Serial Cards
• Wireless Communication Modules